u-boot/arch/arm/mach-mvebu/lowlevel_spl.S
Pali Rohár 701769d87e arm: mvebu: Add documentation for save_boot_params() function
Important detail is availability of kwbimage BIN header arguments passed
via r0 and r1 registers by BootROM.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
2021-10-28 10:33:32 +02:00

79 lines
1.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
#include <config.h>
#include <linux/linkage.h>
/*
* BootROM loads the header part of kwbimage into L2 cache. BIN header usually
* contains U-Boot SPL, optionally it can also contain additional arguments.
* The number of these arguments is in r0, pointer to the argument array in r1.
* BootROM expects executable BIN header code to return to address stored in lr.
* Other registers (r2 - r12) must be preserved. We save all registers to
* CONFIG_SPL_BOOTROM_SAVE address. BIN header arguments (passed via r0 and r1)
* are currently not used by U-Boot SPL binary.
*/
ENTRY(save_boot_params)
stmfd sp!, {r0 - r12, lr} /* @ save registers on stack */
ldr r12, =CONFIG_SPL_BOOTROM_SAVE
str sp, [r12]
b save_boot_params_ret
ENDPROC(save_boot_params)
ENTRY(return_to_bootrom)
ldr r12, =CONFIG_SPL_BOOTROM_SAVE
ldr sp, [r12]
ldmfd sp!, {r0 - r12, lr} /* @ restore registers from stack */
mov r0, #0x0 /* @ return value: 0x0 NO_ERR */
bx lr /* @ return to bootrom */
ENDPROC(return_to_bootrom)
/*
* cache_inv - invalidate Cache line
* r0 - dest
*/
.global cache_inv
.type cache_inv, %function
cache_inv:
stmfd sp!, {r1-r12}
mcr p15, 0, r0, c7, c6, 1
ldmfd sp!, {r1-r12}
bx lr
/*
* flush_l1_v6 - l1 cache clean invalidate
* r0 - dest
*/
.global flush_l1_v6
.type flush_l1_v6, %function
flush_l1_v6:
stmfd sp!, {r1-r12}
mcr p15, 0, r0, c7, c10, 5 /* @ data memory barrier */
mcr p15, 0, r0, c7, c14, 1 /* @ clean & invalidate D line */
mcr p15, 0, r0, c7, c10, 4 /* @ data sync barrier */
ldmfd sp!, {r1-r12}
bx lr
/*
* flush_l1_v7 - l1 cache clean invalidate
* r0 - dest
*/
.global flush_l1_v7
.type flush_l1_v7, %function
flush_l1_v7:
stmfd sp!, {r1-r12}
dmb /* @data memory barrier */
mcr p15, 0, r0, c7, c14, 1 /* @ clean & invalidate D line */
dsb /* @data sync barrier */
ldmfd sp!, {r1-r12}
bx lr